Air ejectob



Patented Sept. 14, 1926.

UNHTETP JOHN E. SMITH, OF FHILADELPI-IIA, PENNPSYLVAI EIA, J iEQIG-NOIEL TO "WESTINGHOUSE ELECTRIC AND MANUFACTURING- COMPANY, 13. COTJLPOR-ATIGN OF PENNSYLVANIA.

AIR EZFE CI'OR.

Application filed July 19,

My invention relates to air ejectors, particularly to that class of ejectors employed for removing non-condensable fluids from condensers, and it has for an object the I production of a steam-operated two-stage intercooled ejector apparatus of the character designated which shall be simple in construction and which shall operate with a high degree and economy of steam consumption.

It has for a further object to provide means for supplying a plurality of cooling mediums of relatively different tempera tures to the intercooler, by the control of which a very fine heat balance may be main tained therein, and an increase or a decrease in the capacity of the ejector effected.

These and other objects of my invention, which will be manifest in the further description thereof, are set forth in the following; specification and illustrated in the following drawing in which Fi 1 is a diagrammatic arrangement of an air ejector apparatus constructed in accordance with my invention; Fig. 2 is a longitudinal sectional elevation of the intercooler employed in Fig. 1; Fig. 3 is a transverse sectional elevation taken on the line TIL-HI of Fig. 2 and Fig. 4 is a, transverse sectional elevation taken on the line IVIV of Fig. 2.

The type of air-removal apparatus frequently employed at the present time consists of a two-stage air ejector operated by steam and having each jet or stage discharging into a cooler. A single cooling medium consisting either of condensate from the main condenser or extraneous water having a low temperature is usually supplied to the cooler. In the former case, the heat of condensation of the motive steam used in the ejectors is absorbed by the condensate and returned to the system, while in the latter, the heat of condensation is lost to the system. The extraneous water having a temperature relatively lower than that of. the condensate, however, the air discharged by the first-stage ejector is cooled an additional amount sufficient to permit a considerable reduction in the specific vol ume thereof and the amount of vapor entrained therein, which consequently permits the operation of the second-stage ejector with a reduced expenditure of motive steam. In a few instances, both condensate and en traneous water have been simultaneously 1923. Serial ire. 651,833.

supplied to respective portions of the cooler, and, under conditions of normal operation, very good efiiciencies have been obtained.

By my invention, T supply control means whereby condensate may be supplied as a cooling medium to the entire cooled or, under abnormal conditions of operation, a portion of the cooler may be isolated from the condensate supplying means, and extraneous water of a relatively lower temperature supplied thereto.

By means of this selective control of cooling mediums of relatively different tempera tures, it is possible to maintain a substantially perfect heat balance in the intercooler under operating conditions which may vary the load, vacuum, circulating water temperature, condensate temperature, and amount of air leakage. Furthermore, a substantial increase in the capacity and working; range of the air ejector may be effected.

Referring to the drawing: for a more detailed description of my invention, in Fig. 1 I have indicated at a surface condenser of the conventional type. Exhaust steam from a prime mover is admitted to the condenser through the inlet opening 11. Air is removed from the condenser through the opening; 12 and is conveyed through the conduit 13 to one or more first-stage ejectors 14. The air thus delivered to the ejector is entrained therein by steam under pressure admitted through the inlet pipe 15 and valve 16, and is discharged through a diffuser 1?, and a conduit 18 to an intercooler 19.

The intercooler 19, shown in Figs. 2, 3 and 4t, is composed of a central casing 21 having a first-stage chamber 22 and a second-stage chamber 523. Each chamber is provided with respective inlet nozzles 24 and 25 and remotely disposed therefrom are air outlet nozzles 26 and 27 and condensate outlet nozzles 28 and 29. The casing 21 has, at its end portions, outwardly-extending flanges 31 and 32. Secured to these flanges are two tube sheets 83 and 84; arranged to receive tubes 85 which extend through both the first-stage and second-stage chambers. The inlet water box and the outlet Water box 37 are secured in any suitable manner to the casing 21 at the edges of each of the tube sheets 33 and 3%. The water boxes 36 and 3? are divided by a partition 38 into two Illl Elli

. the inlet nozzle Qel water-tight compartments 39 and do com- .municating respectively with the tubes in the inlet and outlet portions of both the first-stage and second-stage chambers. For

and 45 are provided in the outlet box 37.

The combined steam and by the first-stage ejector ll into the her 22 wherein the air and :team are rated, and the air dischar 'ed th through the outlet nozzle 26 and the conduit 46 to one or more second-stage ejectors ll. The air thus delivered to the ejector is co trained therein by steam under pressure admitted through the inlet pipe 48 and valve ii), and is discharged through a dill'user 5i and conduit 52 to the inlet nozzle 25 oi? the second-stage chamber 23 oil. the intereooler. Within this chamber the air and steam are separated, and the air passes through the outlet nozzle 27 to the atmosphere. The steam is condensed and passes throrugh the outlet nozzle 29 to the feed tank.

The circulating water for the inter-coole is taken from the hotwell 53 oi the main condenser 10, and also from an extraneous source having a relatively lower temperature. As illustrated, a conduit leads from the hotwell 53 to the condensate pump 55, and the condensate is discharged by the pump through the conduit 56 to a fitting; 57 having two outlet nozzles. One of hese nozzles connnunicates freely with the oircu lating water inlet nozzle 42, for supplying cooling water to the inlet portion oi the central chamber, and the second outet nozzle communicates through a shutotl valve and fitting 59 with the inlet noz lo ror supplying cooling water to the outl portion of the central chamber. For supplying relatively colder water to this portion of the central chamber, the lit-inc 59 has a second inlet nozzle which receives extraneous water through the conduit 62 and shut-ell valve 61.

lhe circulating Waters supplied to the com part-ments 39 and 40 of the inlet water box 36, pass independently through the tubes 35 to similarly arranged compartments in the outlet water box 37 and thence through outlet nozzle i l; and 45 to conduits 63 and 6. respectively. The conduit 63 leads to feed tank, while the conduit 64-, which may convey either condensate supplied from the main condenser or water supplied from an extraneous source, is provided with a :littiiur 65 having two outlet nozzles. These outlet nozzles are provided with valves 66 and 67, respectively, through the operation oil which extraneous water may be discharged from the system through the conduit 38 or condensate discl irged to the teed tank in common with the condensate from the adjacent compurtment through the tilting (ll a d conduit 70.

ilaviug thus described the arrangement of an :u iparalus embodying one term ol my 'uventiom the operation thereof is as follows: Exhaust steam is delivered to the condemacr ill through the inlet opening: ll. i am comlcnsiul and collects in the hoiuiil ht). 'lhe air and llUll-(Ulltltflll-ldllli. gases are removed lhrougrh the outlet iii and conduit ll) to the tirststage ejector l-l. t /team under pres ire supplied through the pipe lil ll'llVm the air From the conduit it and eomieimeutly trom the conclouser lo and discharges this mired steam and air at increased PlCF-t e into tlul'o tap e 22) ot the L: rcoolcr ill. ll ilhin 101'. the mixed steam and air come with the (Utillllfi tubes 235i and the is Cililtltlli-Ttltl and separated from the The coudcuscil stezuu thors throiui h the llct nozzle to the main condenser. while is; withdrawn by the second-st:

ll ll All il ithin this ejector: the preshe air is raised to a little above ati h means ol? steam under pres delivered through the pipe ill. The l steam and air discharged by this n is delivered to the secoml-slapjo charm of the intorcooler ill, wherein the steam is comlensed and separated air. The condensed steam 'llows pgh the outlet nozzle 29 to the teed tauln the a J passes out through the nozzle the atmosphere.

or normal operating conditions, the

line- 'u'ater supplied to the intercoolcr 1 usate from the luiitwcll fill of the main condenser 10. The "elves (ii and (3? heingz; closed, and the valves 5% and (so being opem pump llii dis-whar res condensate too ih oua'h the conduit Fill to holu oi the compartments 39 and lO oi": the inlet water box 36. The streams ot' condimsatc llow rez-xpeetive tuhes 3:3 in the .cr to the outlet water hm: I'll. ro-uuited in the conduit 70. hr'iwcvwr the amount of condensate do. oi the tem ieruturc thereof he .itlv lov: lo the proper aosorp- 1 l cat ol (OD tlQil .-dl'iO1l oi the moare tiho u d be ieu be admitted to substantially hall the numher oi coolmn' tubes. Th s will result in sulr' tanjtiall v doubling the sumily of cooling.

mediun'i to the remaining tubes. The above lOO condensate.

operation may be accomplished by closing the valves 58 and 66 and opening the valves 61 and 67, by which, the condensate discharged from the pump 55 passes only through the tubes in communication with the compartment 89 of the inlet water box 56 and thence through the conduit 63 to the feed tank. The remaining tubes, which are in communication with the compartment l-O of the inlet water, box 36, are supplied through the conduit 62 with water of a temperature relatively lower than that of the This water is conveyed independently through the tubes and discharge water chest 37, and the conduits 64 and 8 to some point outside of the system.

As shown, the intercooler is preferably arranged so that the discharge from the ejectors comes, in contact, first with that portion of the tube nest through which is being circulated condensate, and subsequently through the remaining portion of the tube nest through which is being circulated colder water. The mixed steam and air discharged by the ejectors is therefore successively cooled in passing over the tubes, also the heat of condensation of the motive steam discharged by the ejectors is substantially absorbed by the condensate, and thereby returned to the plant.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is 2- 1. In combination with a high vacuum condenser provided with two pumps connected in series for withdrawing air and vapor therefrom, the first of said pumps being a steam operated ejector pump, a cooling device for absorbing the heat of the steam utilized in the ejector, means for supplying a cooling medium to the device and means for shutting off the supply of cooling medium to a portion of the device and for supplying a medium of relatively different temperature thereto.

2. In combination with a high vacuum condenser provided with a two-stage ejector for withdrawing air and vapor therefrom, a cooler interposed between the stages for absorbing the heat of the steam utilized in the first stage of the ejector, a plurality of tubes within said cooler, means for supplying condensate to the tubes, and means for turning off the supply of condensate to a portion of the tubes and for supplying extraneous water thereto.

3. In combination with a condenser provided with two steam-operated ejector pumps connected in series for withdrawing the air and vapor therefrom, a device for receiving the discharge of the pumps, a plurality of groups of cooling tubes therein, means for supplying condensate to the tubes, and'means for shutting off the supply of condensate to some of the groups of tubes and for supplying relatively colder water thereto.

a. In combination with a condenser provided with a plurality of steam-operated ejectors connected in series for the withdrawal of air and vapor therefrom, a cooler for each ejector receiving the discharge therefrom, a plurality of tubes within each cooler, means for supplying condensate to the tubes, and means for shutting off the supply of condensate to a portion of the tubes in each cooler and for supplying water of a relatively lower temperature thereto.

5. In condensing apparatus, the combination of a first-stage ejector and a secondstage ejector, a device having a first-stage chamber for receiving the discharge of the first-stage ejector and having a second-stage chamber for receiving the discharge of the second-stage ejector, means for connecting the inlet of the secondetage ejector to the first-stage chamber, cooling tubes passing through the chambers, separate water boxes for groups of cooling tubes, means for supplying the same cooling medium to all of said boxes and means for shutting off said cooling medium from one of the bones and for supplying a relatively cooler medium thereto.

6. In condensing apparatus, the combina tion of a first-stage ejector, a second-stage ejector, a receptacle having a first-stage chamber provided with inlet and outlet nozzles, said inlet nozzle receiving the discharge from the first-stage ejector, and a second-stage chamber provided with inlet and outlet nozzles, said inlet nozzle for receiving the discharge from the second-stage ejector, means for connecting the outlet nozzle of the first-stage chamber to the inlet of the second-stage ejector, a plurality of tubes within each chamber, means for supplying condensate to all the tul es, and means for shutting elf the supply of condensate to that portion of the tubes in the vicinity of the outlet nozzles in the first and second-stage chambers and for supplying extraneous water thereto.

7. In condensing apparatus, the combination of a first-stage ejector, a second-stage ejector, a device having a first-stage chamber,-and a secondstage chamber, an inlet nozzle provided in the first-stage chamber for receiving the discharge from the firststage ejector, an outlet nozzle provided in the first-stage chamber remotely disposed to the inlet nozzle, said outlet nozzle communieating With the inlet of the second-stage means for shutting oil said condensate to ejector, an inlet nozzle provided in the the waterbox communicating with the tubes second-stage chamber for receiving the disin the outlet portion of each chamber and charge from the second-stage ejector, a plufor supplying Water of a relatively lower 5 rality of cooling tubes within each chamber temperature thereto.

independent Water boxes comn'iunicating In testimony whereof, I have hereunto With the tubes in the inlet portions of each subscribed my name this 3rd day oi? July, chamber and the outlet portions of each 1923.

chamber respectively, means for supplying m condensate to both ol said Water boxes, and JOHN H. Slrlllll 

